William Terzaghi

Spring 2014

Bio 398: Topics in Plant Biology

COURSE OVERVIEW1) Understanding how plants work.2) Understanding how plant biologists work.

• Method• Technology

COURSE OVERVIEW1) Understanding how plants work.2) Understanding how plant biologists work.

• Method• Technology

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12914.html

COURSE OVERVIEW1) Understanding how plants work.2) Understanding how plant biologists work.

• Method• Technology

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12914.htmlhttp://www.cbc.ca/news/technology/older-trees-grow-faster-than-

younger-ones-study-finds-1.2499298

Plan CWe will pick a problem in plant biology and see where it takes us.1.Biofuels 2.Climate/CO2 change3.Stress responses/stress avoidance• Structural• Biochemical (including C3 vs C4 vs CAM)• Other (dormancy, carnivory, etc)

4.Plant products• Defense compounds

5.Improving food production• Breeding: new traits to pick & ways to find them• GMO• New crops

6.Biotechnology7.Phytoremediation 8.Plant movements9.Plant signaling (including neurobiology)

Plan C

1.Pick a problem

Plan C

1.Pick a problem2.Pick some plants to study

Plan C

1.Pick a problem2.Pick some plants to study3.Design some experiments

Plan C

1.Pick a problem2.Pick some plants to study3.Design some experiments4.See where they lead us

Plan C

1.Pick a problem2.Pick some plants to study3.Design some experiments4.See where they lead us

Grading?Combination of papers and presentations

Plan C

1.Pick a problem2.Pick some plants to study3.Design some experiments4.See where they lead us

Grading?Combination of papers and presentationsScavenger hunts?

Plan CGrading?

Combination of papers and presentations•First presentation:10 points •Research presentation: 10 points •Final presentation: 15 points •Assignments: 5 points each•Poster: 10 points•Intermediate report 10 points•Final report: 30 points•Scavenger hunts?

BIO 398- Resource and Policy Information

Instructor: Dr. William TerzaghiOffice: SLC 363/CSC228Office hours: MWF 12-1 in CSC228, T 1-2 in SLC 363, Thurs 1-2 in CSC228, or by appointmentPhone: (570) 408-4762Email: terzaghi@wilkes.edu

BIO 398 - Resource and Policy Information

Instructor: Dr. William TerzaghiOffice: SLC 363/CSC228Office hours: MWF 12-1 in CSC228, T 1-2 in SLC 363, Thurs 1-2 in CSC228, or by appointmentPhone: (570) 408-4762Email: terzaghi@wilkes.edu

Course webpage: http://staffweb.wilkes.edu/william.terzaghi/bio398.html

Vegetative Plants3 Parts

1. Leaf2. Stem3. Root

Vegetative Plants3 tissue types

1. Dermal2. Ground3. Vascular

Plant Development• Cell division = growth

Plant Development• Cell division = growth• Determination = what cell can become

Plant Development• Cell division = growth• Determination = what cell can become• Differentiation = cells become specific types

Plant Development• Cell division = growth• Determination = what cell can become• Differentiation = cells become specific types• Pattern formation: developing specific structures in

specific locations

Plant Development• Cell division = growth• Determination = what cell can become• Differentiation = cells become specific types• Pattern formation• Morphogenesis: organization into tissues & organs

Plant Developmentumbrella term for many processes• embryogenesis

Plant Development

umbrella term for many processes• Embryogenesis• Seed dormancy and germination

Plant Development

umbrella term for many processes• Embryogenesis• Seed dormancy and germination• Seedling Morphogenesis

Plant Developmentumbrella term for many processes• Embryogenesis• Seed dormancy and germination• Seedling Morphogenesis• Transition to flowering, fruit and seed formation

Plant Developmentumbrella term for many processes• Embryogenesis• Seed dormancy and germination• Seedling Morphogenesis• Transition to flowering, fruit and seed formation Many responses to environment

Plant DevelopmentUmbrella term for many processesUnique features of plant development• Cell walls: cells can’t move: Must grow towards/away from signals

Plant DevelopmentUmbrella term for many processesUnique features of plant development• Cell walls: cells can’t move: must grow instead• Plasticity: plants develop in response to environment

Unique features of plant development• Cell walls: cells can’t move• Plasticity: plants develop in response to environment• Totipotency: most plant cells can form an entire new

plant given the correct signals

Unique features of plant development• Cell walls: cells can’t move• Plasticity: plants develop in response to environment• Totipotency: most plant cells can form an entire new

plant given the correct signals• Meristems: plants have perpetually embryonic regions,

and can form new ones

Unique features of plant development• Cell walls: cells can’t move• Plasticity: plants develop in response to environment• Totipotency: most plant cells can form an entire new

plant given the correct signals• Meristems: plants have perpetually embryonic regions,

and can form new ones• No germ line!

Unique features of plant development• Meristems: plants have perpetually embryonic regions,

and can form new ones• No germ line! Cells at apical meristem become flowers: allows Lamarckian evolution!

Unique features of plant development• Meristems: plants have perpetually embryonic regions,

and can form new ones• No germ line! Cells at apical meristem become flowers: allows Lamarckian evolution!• Different parts of the same 2000 year old tree have

different DNA & form different gametes

Plant Cell Theory

1) All organisms are composed of one or more cells

Plant Cell Theory

1) All organisms are composed of one or more cells

2) Cell is smallest living organizational unit

Plant Cell Theory

1) All organisms are composed of one or more cells

2) Cell is smallest living organizational unit

3) Cells arise by division of preexisting cells

Plant Cells1) Highly complex and organized

Plant Cells1) Highly complex and organized

2) Metabolism

Plant Cells1) Highly complex and organized

2) Metabolism

3) Reproduction

Plant Cells1) Highly complex and organized

2) Metabolism

3) Reproduction

4) Heredity

Plant Cells1) Highly complex and organized

2) Metabolism

3) Reproduction

4) Heredity

5) Mechanically active

Plant Cells1) Highly complex and organized

2) Metabolism

3) Reproduction

4) Heredity

5) Mechanically active

6) Respond to stimuli

Plant Cells1) Highly complex and organized

2) Metabolism

3) Reproduction

4) Heredity

5) Mechanically active

6) Respond to stimuli

7) Homeostasis

Plant Cells1) Highly complex and organized

2) Metabolism

3) Reproduction

4) Heredity

5) Mechanically active

6) Respond to stimuli

7) Homeostasis

8) Very small

Why are cells so small?1) many things move inside cells by diffusion

Why are cells so small?1) many things move inside cells by diffusion2)surface/volume ratio

Why are cells so small?1) many things move inside cells by diffusion2) surface/volume ratio

• surface area increases more slowly than volume

Why are cells so small?1) many things move inside cells by diffusion2) surface/volume ratio

• surface area increases more slowly than volume• exchange occurs only at surface• eventually have insufficient exchange for survival

Plant Cells1) Cell walls

• Carbohydrate barriersurrounding cell

Plant Cells1) Cell walls

•Carbohydrate barriersurrounding cell•Protects & gives cell shape

Plant Cells1) Cell walls

• Carbohydrate barriersurrounding cell• Protects & gives cell shape• 1˚ wall made first

• mainly cellulose

Plant Cells1) Cell walls

• Carbohydrate barriersurrounding cell• Protects & gives cell shape• 1˚ wall made first

• mainly cellulose• Can stretch!

Plant Cells1) Cell walls

• Carbohydrate barriersurrounding cell• Protects & gives cell shape• 1˚ wall made first

• mainly cellulose• Can stretch!

• 2˚ wall made after growth stops

Plant Cells1) Cell walls

• Carbohydrate barriersurrounding cell• Protects & gives cell shape• 1˚ wall made first

• mainly cellulose• Can stretch!

• 2˚ wall made after growth stops

• Lignins make it tough

Plant Cells1) Cell walls

• Carbohydrate barriersurrounding cell• Protects & gives cell shape• 1˚ wall made first

• mainly cellulose• Can stretch!

• 2˚ wall made after growth stops

• Lignins make it tough• Problem for "cellulosic Ethanol" from whole plants

Plant Cells1) Cell walls

• 1˚ wall made first• 2˚ wall made after growth stops

• Lignins make it tough• Problem for "cellulosic Ethanol" from whole plants

• Middle lamella = space between 2 cells

Plant Cells1) Cell walls

• 1˚ wall made first• 2˚ wall made after growth stops• Middle lamella = space between 2 cells• Plasmodesmata = gaps in walls that link cells

Plant Cells• Plasmodesmata = gaps in walls that link cells

• Lined with plasma membrane

Plant Cells• Plasmodesmata = gaps in walls that link cells

• Lined with plasma membrane• Desmotubule joins ER of both cells

Plant Cells• Plasmodesmata = gaps in walls that link cells

• Lined with plasma membrane• Desmotubule joins ER of both cells• Exclude objects > 1000 Dalton, yet viruses move through them!

Types of Organelles1) Endomembrane System2) Putative endosymbionts

Endomembrane systemCommon features

• derived from ER

Endomembrane systemCommon features• derived from ER• transport is in vesicles

Endomembrane systemCommon features• derived from ER• transport is in vesicles• proteins & lipids are glycosylated

Endomembrane systemOrganelles derived from the ER1) ER2) Golgi3) Vacuoles 4) PlasmaMembrane5) Nuclear Envelope6) Endosome7) Oleosomes

ERNetwork of membranes t/out cell2 types: SER & RER

SERtubules that lack ribosomesfns:1) Lipid syn2) Steroid syn3) drug detox4) storing Ca2+

5) Glycogen catabolism

RERFlattened membranes studded with ribosomes1˚ fn = protein synthesis -> ribosomes are making proteins

ERSER & RER make new membrane!

GOLGI COMPLEXFlattened stacks of membranes made from ER

GOLGI COMPLEXIndividual, flattened stacks of membranes made from ERFn: “post office”:collect ER products, process & deliver themAltered in each stack

GOLGI COMPLEXIndividual, flattened stacks of membranes made from ERFn: “post office”:collect ER products, process & deliver themAltered in each stackMakes most cell wall carbohydrates!

GOLGI COMPLEXIndividual, flattened stacks of membranes made from ERFn: “post office”:collect ER products, process & deliver themAltered in each stackMakes most cell wall carbohydrates!Protein’s address isbuilt in

VACUOLESDerived from Golgi; Fns: 1)digestion

a) Organellesb) food particles

VACUOLESDerived from Golgi; Fns:1)digestion

a) Organellesb) food particles

2) storage

VACUOLESDerived from Golgi; Fns:1) digestion

a) Organellesb) food particles

2) storage3) turgor: push plasma membrane against cell wall

VACUOLESVacuoles are subdivided: lytic vacuoles are distinctfrom storage vacuoles!

Endomembrane systemOrganelles derived from the ER1) ER2) Golgi3) Vacuoles 4) PlasmaMembraneRegulates transport in/out of cell

Endomembrane systemOrganelles derived from the ER1) ER2) Golgi3) Vacuoles 4) PlasmaMembraneRegulates transport in/out of cellLipids formbarrierProteins transportobjects & info

Endomembrane System5) Nuclear envelope: regulates transport in/out of nucleusContinuous with ER

Endomembrane System5) Nuclear envelope:regulates transport in/out of nucleusContinuous with ERTransport is only through nuclear pores

Endomembrane System5) Nuclear envelope:regulates transport in/out of nucleusContinuous with ERTransport is only through nuclear poresNeed correct signal& receptor for import

Endomembrane System5) Nuclear envelope: regulates transport in/out of nucleusContinuous with ERTransport is only through nuclear poresNeed correct signal& receptor for import new one for export

Endomembrane SystemNucleus: spherical organelle bounded by 2 membranes and filled with chromatin = mix of DNA and protein

Endomembrane SystemNucleus: spherical organelle bounded by 2 membranes and filled with chromatin fns = information storage & retrievalRibosome assembly (in nucleolus)

Endomembrane SystemEndosomes: vesicles derived from Golgi or Plasma membraneFn: sorting materials & recycling receptors

Endomembrane SystemOleosomes: oil storage bodies derived from SERSurrounded by lipid monolayer!

Endomembrane SystemOleosomes: oil storage bodies derived from SERSurrounded by lipid monolayer!

• filled with lipids: no internal hydrophobic effect!